Space garment



Nov. 19, 1968 8.1. FEHER 4 .,3,4ll,156

SPACE GARMENT Filed March 17. 1965 United States Patent O 3,411,156 SPACE GARMENT Stephen I. Feher, San Diego, Calif., assignor to Whittaker Corporation, Los Angeles, Calif., a corporation of California Filed Mar. 17, 1965, Ser. No. 440,535 6 Claims. (Cl. 2-2.1)

ABSTRACT OF THE DISCLOSURE A heat transfer system for a garment for use in space in which heat exchanger fluid is circulated from the irradiated side to the unirradiated side of the garment and in which expandable bimetallic elements cause the heat eonductivity of the unirradiated side to be greater than that of the irradiated side.

This inventon relates to a heat transmission system and more particularly relates to a heat transmission system for a space garment including variable eonductivity insulation and liquid heat transmission.

Presently proposed space garments use highly reflective external skins combined With a circulating cooling fluid which carries heat energy from the garment to an external heat exchanger unit. The equipment available to serve as the external heat exchanger unit is relatively bulky and heavy and limits the wearer's mobility. According to the present inventon, a heat transmission system for a space garment is provided which eliminates the need for a bulky external heat exchanger.

It is therefore an object of the present inventon to provide a heat transmission system for a space garment in which a cooling fluid is circulated but which requires no external heat exchanger.

It is also an object of the present inventon to provide such a system in which the eonductivity of the space surrounding the cooling fluid is variable.

It is another object of the present inventon to provide a space garment in which the hot side of the garment has a very low heat conductivity and the cold side of the garment has a high heat eonductivity so that heat energy absorbed by a circulating cooling fluid on the hot side of the garment can be transferred to the exterior by radiation on the cool side.

These and other objects and advantages of the present inventon will become more apparent upon reference to the accompanying description and drawings in which:

FIGURE l is a perspective view, partly broken away, showing the space garment of the present inventon in use;

FIGURE 2 is a detailed sectional view of a portion of the heat transmission system of the space garment of the present inventon when it is raised to a high temperature;

FIGURE 3 is a detailed sectional view of the same portion of the space garment of the present inventon exposed to a low temperature;

FIGURE 4 is a cross-sectional view taken along 4-4 of FIGURE 2; and

FIGURE 5 is a cross-sectional view taken along lines 5-5 of FIGURE 3.

Turning now to FIGURE 1, there is shown a space garment including a temperature dependent variable eonductivity heat transmission system 12 which is shown partly broken away. A cooling fluid is circulated within the system 12 by means of a pump 14. The circulating cooling fluid can also be passed to and from the helmet 1d by means of a conduit 18.

The details of the heat transmission system are shown in FIGURES 2 through 5, FIGURES 2 and 4 showing the system in the position that it would assume when the ICC irradiation heat flow is high as a result of solar radiation. FIGURES 3 and 5 show the system in the position it assumes when the external surface is at a low temperature. The system includes an impermeable external skin 24 which is constructed of a suitable material, for example,

a Synthetic fabric such as Fortisan or Dacron impreg-l -nated with polyurethane or polyethylene resin. The external skin is coated with an optical thermal control material 25 having a low solar radiation absorptivity to thermal emissivity ratio. In other words, the material should be highly emissive for long wavelength infrared but at the same time highly reflective for direct solar radiation. An example of such a coating is a thin fluorocarbon film over aluminum foil.

Engaging the inner surface of the external skin 24 is -a plurality of bimetallic thermal springs 26. These bimetallic thermal Springs may simply be bimetallic strips arranged in a spiral pattern and curling outwardly when heated. A fiexible tubing 30 carrying any suitable cooling liquid is also wrapped in a spiral pattern, the coils of the tubing being interspersed between the rows of bimetallic Springs. A refiection membrane 32 is fastened to the outer surface of the tubing 30. This membrane may be made of any suitable refiecting material. The fiexible tubing 30 and the inner ends of the bimetallic thermal Springs 26 are fastened in any suitable manner to a fiexible insulation layer 34, for example, of conventional honeycomb construction. The inner surface of the fiexible insulation layer 34 is provided with an internal skin 36 of any suitable material, for example, a Synthetic fabric such as Dacron.

The operation of the system can be seen by comp-aring FIGURES 2 and 4 with FIGURES 3 and 5. On the lighted side of the garment where the irradiation heat flow is high from solar radiation, the skin temperature is high. The bimetallic thermal Springs expand and curl outwardly due to the high external skin temperature, causing a vacuum space 28 to be `formed which serves as effective insulation against conducted heat transfer. The refiection membrane 32 further minimizes the heat fiow from the outside surface inward. The small amount vof heat flow not reflected by the membrane is absorbed by the circulating fiuid in the tubing 30. Heat flow from the interior surfaces is also absorbed by the heat exchanger fluid The heat exchanger fluid is carried to the dark side of the garment where the external surface is at a low temperature and the bimetallic thermal Springs 26 are in the retracted position. As a result, there is direct contact between the heat exchanger tubing 30, the reflective membrane 32, and the external skin 24, providing a good conductive heat path from the circulating fluid to the outer skin surface. The heat energy absorbed by the circulating fluid on the hot side of the garment and the heat flow from the interior of the garment is transmitted to the outside skin on the dark side and radiated into space. The small pump 14 is sufficient to circulate the heat eX- changer fiuid and thus the bulk of the garment is considerably reduced.

-From the foregoing description, it can be seen that a space garment has been provided that eliminates the need for an external heat exchanger. While the description has been solely in the terms of a space garment, it should be obvious that\the variable eonductivity heat transmission systemv described could be used for any object for which maintaining a closely Controlled internal temperature is important and where there is only limited space available for heat exchanger apparatus. The inventon may therefore be embodied in other specific forms not departing from the spirit or central characteristics thereof. The present embodiment is therefore to be considered in all respects as illnstrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are theref-ore intended to be embraced therein.

I claim:

1. A heat transmission system for an object having one side at a high temperature and another side at a lower temperature comprising: a layer of insulating material adapted to surround said object, fluid conduit means adapted to extend around said object and overlying said insulating layer, a body of heat exchanger fluid positioned `in said conduit means, means for circulating said fluid in said conduit means, an outer skin overlying said fluid conduit means and relatively movable therewith, and thermally responsive means positioned between said insulating layer and said outer skin, said thermally responsive means expanding to position said outer skin away from said fluid conduit means when heated to a high temperature and retracting to position said outer skin adjacent said fluid conduit means when not heated to a high temperature.

2. A heat transmission system for an object having one side at a high temperature and another side at a lower temperature, comprising: a layer of insulating material adapted to surround said object, fluid conduit means adapted to extend around overlying said insulating layer, a body of heat exchanger fluid positioned in said conduit means, means for circulating said fluid in said conduit means whereby said fluid travels from said high temperature side to said lower temperature side, an outer impermeable skin overlying said fluid conduit means, and relatively movable therewith, and thermally responsive means positioned between said insulating layer and said outer skin on both high and lower temperature sides, said thermally responsive means expanding to position said outer skin away from said fluid conduit means and cause a vacuum space to be formed therebetween when heated to a high temperature as a result of being located on said high temperature side and retracting to position said outer skin adjacent said fluid conduit means when not heated to a high temperature as a result of being on the lower temperature side.

3. A heat transmission system vfor an object having one side at a high temperature and another side at a lower temperature, comprising: a layer of insulating material adapted to surround said object, a fluid carrying tubing mounted on and wrapped around said layer of insulating material, a body of heat exhanger fluid positioned in said tubing, means for circulating said fluid in said tubing whereby said fluid is carried from said high temperature side to said lower temperature side and back again, an

outer skin overlying said tubing and relatively movable therewith, said outer skin being coated with optical thermal control material having a low solar radiation absorptivity to thermal emissivity ratio, and thermally responsive means positioned between said insulating layer and said outer skin, said thermally responsive means when on said high temperature side being caused to expand to position said outer skin away from said tubing and form a vacuum space therebetween, and when positioned on said lower temperature side, being retracted to position said outer skin adjacent said tubing.

4. The heat transmission system of claim 3 wherein said tubing is provided with a reflective membrane.

5. In a space garment including a torso portion the combination of a layer of insulating material extending around the torso portion of said garment, a fluid carrying mult-coil tubing mounted on and wrapped around said insulating layer, a body of heat exchanger fluid positioned in said tubing, pump means for eirculating said fluid in said tubing whereby said fluid is continuously circulated about said torso portion, and impermeable outer skin overlying said tubing and relat'ively movable therewith, said outer skin 'being coated with an optical thermal control material having a low solar radiation absorptivity to thermal emissivity ratio, 'a plurality of bimetallic thermal springs positioned between the coils of said tubing and having one end mounted on said insulating layer and the other end engaging said outer skin, said bimetallic thermal Springs expanding to position said outer skin away from said tubing to form a vacuum space therebetween when said outer skin is heated by solar radiation so that heat transfer from said outer skin to said fluid in said tubing is minimized, and retracting when said outer skin is not heated by solar radiation to position said outer skin adjacent said tubing whereby a good conductive heat path is provided between said fluid and said outer skin.

6. The garment of claim 5 wherein said tubing is provided with a reflective membrane.

References Cited UNITED STATES PATENTS 2,637,530 5/1953 Janos -136 2,671,441 3/1954 Harris 165-136 X 2,949,283 8/1960 Smith 165-96 X 2,966,684 1/1961 Bonin 2-81 3,079,765 3/ 1963 LeVant-ine 62-259 3,130,4l3 4/ 1964 Schueller 2-2.1

JORDAN FRANKLIN, Primary Examiner.

G. KRIZMANICI-I, Assistant Examner. 

